A mechanical linear actuator for an aircraft brake assembly often incorporates a ball screw that transmits axial load from a ball nut, through balls, and to a rotating screw. The axial load from the rotating screw is then transmitted out of the assembly through the use of a thrust bearing to reduce rotary friction torque. The thrust bearing may be an annular ring of balls between the ball screw and an actuator drive unit housing. The balls may be inserted into the annular ring via a window in the ball screw. However, the window may weaken the surrounding area in the ball screw and may result in damage to the ball screw.